Antisera from guinea pigs immunized against individual human rhinovirus (HRV) serotypes were used to determine reactivity in an immunoblot system with the capsid surface peptides (VP1, VP2, VP3) of HRV serotype 14 (HRV14) in a continuation of studies begun with HRV2. HRV14 and HRV2 were purified by CsCl gradient, separated into capsid peptides by electrophoresis through polyacrylamide and transferred to nitrocellulose membranes for immunoblotting. Serum IgG binding was identified by immunoperoxidase methodology. Only the antiserum specific for HRV14 neutralized HRV14 and only the antiserum for HRV2 neutralized HRV2. However, the majority of the antisera against 53 individual serotypes reacted with HRV2 and HRV14. Nine of the antisera reacted with neither HRV and five of the antisera reacted with both. Thirty of the 53 antisera reacted only with HRV2 and 19 reacted only with HRV14. The pattern of reactivity was best correlated with a defined spectrum of susceptibility of the HRV serotypes to antiviral chemicals which stabilize the rhinovirus capsid by binding to a relatively conserved amino acid sequence occupying a fold in the capsid surface of VP1. For both HRV 14 and HRV2, the antibodies identified were directed predominantly against antigenic determinants of VP1, and only infrequently against VP2 or VP3. The data suggest that immunogenic antigenic determinants have been conserved in the evolution of HRV. The identification of antisera for serotypes which react with capsid peptides of both HRV14 and HRV2 or with neither HRV suggests that the antigenic determinants identified may coexist in HRV representing transitions between HRV14 and HRV2, and that unrelated antigenic representing further evolution may be present.